| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dalawlem.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 2 | 
							
								
							 | 
							dalawlem.j | 
							 |-  .\/ = ( join ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							dalawlem.m | 
							 |-  ./\ = ( meet ` K )  | 
						
						
							| 4 | 
							
								
							 | 
							dalawlem.a | 
							 |-  A = ( Atoms ` K )  | 
						
						
							| 5 | 
							
								
							 | 
							dalawlem2.o | 
							 |-  O = ( LPlanes ` K )  | 
						
						
							| 6 | 
							
								
							 | 
							simp11 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> K e. HL )  | 
						
						
							| 7 | 
							
								
							 | 
							simp12 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> -. ( ( P .\/ Q ) .\/ R ) e. O )  | 
						
						
							| 8 | 
							
								
							 | 
							simp22 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> Q e. A )  | 
						
						
							| 9 | 
							
								
							 | 
							simp23 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> R e. A )  | 
						
						
							| 10 | 
							
								
							 | 
							simp21 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> P e. A )  | 
						
						
							| 11 | 
							
								1 2 4 5
							 | 
							islpln2a | 
							 |-  ( ( K e. HL /\ ( Q e. A /\ R e. A /\ P e. A ) ) -> ( ( ( Q .\/ R ) .\/ P ) e. O <-> ( Q =/= R /\ -. P .<_ ( Q .\/ R ) ) ) )  | 
						
						
							| 12 | 
							
								6 8 9 10 11
							 | 
							syl13anc | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( ( Q .\/ R ) .\/ P ) e. O <-> ( Q =/= R /\ -. P .<_ ( Q .\/ R ) ) ) )  | 
						
						
							| 13 | 
							
								
							 | 
							df-ne | 
							 |-  ( Q =/= R <-> -. Q = R )  | 
						
						
							| 14 | 
							
								13
							 | 
							anbi1i | 
							 |-  ( ( Q =/= R /\ -. P .<_ ( Q .\/ R ) ) <-> ( -. Q = R /\ -. P .<_ ( Q .\/ R ) ) )  | 
						
						
							| 15 | 
							
								
							 | 
							pm4.56 | 
							 |-  ( ( -. Q = R /\ -. P .<_ ( Q .\/ R ) ) <-> -. ( Q = R \/ P .<_ ( Q .\/ R ) ) )  | 
						
						
							| 16 | 
							
								14 15
							 | 
							bitri | 
							 |-  ( ( Q =/= R /\ -. P .<_ ( Q .\/ R ) ) <-> -. ( Q = R \/ P .<_ ( Q .\/ R ) ) )  | 
						
						
							| 17 | 
							
								12 16
							 | 
							bitr2di | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( -. ( Q = R \/ P .<_ ( Q .\/ R ) ) <-> ( ( Q .\/ R ) .\/ P ) e. O ) )  | 
						
						
							| 18 | 
							
								2 4
							 | 
							hlatjrot | 
							 |-  ( ( K e. HL /\ ( Q e. A /\ R e. A /\ P e. A ) ) -> ( ( Q .\/ R ) .\/ P ) = ( ( P .\/ Q ) .\/ R ) )  | 
						
						
							| 19 | 
							
								6 8 9 10 18
							 | 
							syl13anc | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( Q .\/ R ) .\/ P ) = ( ( P .\/ Q ) .\/ R ) )  | 
						
						
							| 20 | 
							
								19
							 | 
							eleq1d | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( ( Q .\/ R ) .\/ P ) e. O <-> ( ( P .\/ Q ) .\/ R ) e. O ) )  | 
						
						
							| 21 | 
							
								17 20
							 | 
							bitrd | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( -. ( Q = R \/ P .<_ ( Q .\/ R ) ) <-> ( ( P .\/ Q ) .\/ R ) e. O ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							con1bid | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( -. ( ( P .\/ Q ) .\/ R ) e. O <-> ( Q = R \/ P .<_ ( Q .\/ R ) ) ) )  | 
						
						
							| 23 | 
							
								7 22
							 | 
							mpbid | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( Q = R \/ P .<_ ( Q .\/ R ) ) )  | 
						
						
							| 24 | 
							
								
							 | 
							simp13 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) )  | 
						
						
							| 25 | 
							
								
							 | 
							simp2 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( P e. A /\ Q e. A /\ R e. A ) )  | 
						
						
							| 26 | 
							
								
							 | 
							simp3 | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( S e. A /\ T e. A /\ U e. A ) )  | 
						
						
							| 27 | 
							
								1 2 3 4
							 | 
							dalawlem12 | 
							 |-  ( ( ( K e. HL /\ Q = R /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) )  | 
						
						
							| 28 | 
							
								27
							 | 
							3expib | 
							 |-  ( ( K e. HL /\ Q = R /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) )  | 
						
						
							| 29 | 
							
								28
							 | 
							3exp | 
							 |-  ( K e. HL -> ( Q = R -> ( ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) ) ) )  | 
						
						
							| 30 | 
							
								1 2 3 4
							 | 
							dalawlem11 | 
							 |-  ( ( ( K e. HL /\ P .<_ ( Q .\/ R ) /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) )  | 
						
						
							| 31 | 
							
								30
							 | 
							3expib | 
							 |-  ( ( K e. HL /\ P .<_ ( Q .\/ R ) /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) )  | 
						
						
							| 32 | 
							
								31
							 | 
							3exp | 
							 |-  ( K e. HL -> ( P .<_ ( Q .\/ R ) -> ( ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) ) ) )  | 
						
						
							| 33 | 
							
								29 32
							 | 
							jaod | 
							 |-  ( K e. HL -> ( ( Q = R \/ P .<_ ( Q .\/ R ) ) -> ( ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) ) ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							3imp | 
							 |-  ( ( K e. HL /\ ( Q = R \/ P .<_ ( Q .\/ R ) ) /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) -> ( ( ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							3impib | 
							 |-  ( ( ( K e. HL /\ ( Q = R \/ P .<_ ( Q .\/ R ) ) /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) )  | 
						
						
							| 36 | 
							
								6 23 24 25 26 35
							 | 
							syl311anc | 
							 |-  ( ( ( K e. HL /\ -. ( ( P .\/ Q ) .\/ R ) e. O /\ ( ( P .\/ S ) ./\ ( Q .\/ T ) ) .<_ ( R .\/ U ) ) /\ ( P e. A /\ Q e. A /\ R e. A ) /\ ( S e. A /\ T e. A /\ U e. A ) ) -> ( ( P .\/ Q ) ./\ ( S .\/ T ) ) .<_ ( ( ( Q .\/ R ) ./\ ( T .\/ U ) ) .\/ ( ( R .\/ P ) ./\ ( U .\/ S ) ) ) )  |